E36 LSx Manifolds

[series8217]

Background
I'm currently scoping out the E36 as an LS1/2/7/6/A/etc engine swap candidate. I've worked on lots of swaps in the past (mostly Fieros).

I ran my own engine-swapped Fiero through California's BAR referee program and got it to pass, so I'm no stranger to the politics here either.

The way it works in Cali is your engine change has to be inspected and approved by a California Bureau of Automotive Repair (BAR) referee, who enforces the rule that all smog equipment from the donor vehicle is present and intact. "Smog equipment" includes everything from sensors to exhaust manifold, evap system, etc.

Obviously, the the big ol' problem with making a street-legal LSx E36 in Cali is there are no options for exhaust. I have to use OEM exhaust manifolds -- or at least something that looks OEM enough that the BAR referee won't ask.

Theoretically, CARB-approved aftermarket headers (they have to have a CARB "EO" number for the donor vehicle) could also pass. I'm not aware of any block-hugger or shorty CARB-approved headers out there that could work, but maybe you are, so please post.

A quick disclaimer: The performance hit is a non-issue in this discussion. This is about passing the smog inspection ONLY. Theoretically, after passing the test at the BAR ref, I can go home and put Vorshlag swap headers on and just go back to the OEM-look manis on for inspection every other year (or if I get cited during a traffic stop).

Question
What OEM LS1/2/3/6/7/A/9/etc exhaust manifolds are close enough to fitting that they can be made to work by doing some creative cutting and welding? I should easily be able to get away with cutting off the flange, and other minor modifications (modifying/removing the heat shield, grinding on or slightly rerouting tubes) should pass as well.

I emailed Terry Fair and got a helpful reply from him directing me to this forum. He mentioned that he saw an E36 LS1 build where someone cut up and welded OEM manifolds to get them to work. Does anyone know whose build it was? I haven't been able to find that thread, but I did find someone who did that for an E39.

LS4?
One thing that nobody on this forum has ever mentioned is the LS4 driver's side manifold. The LS4 was a transverse LS-series motor in 3rd-gen w-bodies like the 2008 Impala SS. The exhaust configuration is like a typical GM FWD car: the front manifold (driver side for RWD) outlet goes to a crossover pipe which takes exhaust over the transmission bellhousing and into a merge at the passenger side pipe. The crossover solution obviously doesn't fit in an E36, but the manifold could be useful. It's extremely restrictive (the LS4 is a 300hp 5.3L) so power output will blow, but if it passes, it passes.

Pic here: http://www.gmtuners.com/LS4/exh_manifolds.jpg
It's the top manifold. You can also see it on the motor here: http://www.gmtuners.com/Customer/LS4_Fiero/LS4_c.jpg
And here:
http://www.zorly.com/images_corvette...mpala%20SS.jpg

Notice the flange is tiny and points straight back.

* - Side note: The LS4 accessory system is awesomely compact, since it's designed to be mounted transversely with a big automatic transmission.

[invictuse36]

If you look at all the headers made for the e36 swap, they are all very block forming while having the magical amount of clearance for the steering shaft. That is why many people (fair, braap, ect) report that NO GM manifolds will work.

I'm thinking about returning to Cali some day with a ls swapped e36, and I'm probably just gonna register the car to Tx, AZ, or just keep it as NV. However if you do make some headers fit, maybe you can loan them out to others that want to get them certified.

Thanks for the heads up on the FEADS as its always good to have more options.

[Kaane]

All the manifolds were tried with exception of the LS4, but I don't think that will fit either.

Check out Braap's post on ls1 tech.

http://ls1tech.com/forums/14204144-post81.html

[rao]

No matter how many times people ask the question, the answer doesn't change

[invictuse36]

http://vorshlag.smugmug.com/Product-..._MxsCR-O-1.jpg

You can see in the top right hand corner why headers need to be purpose built to work around the steering shaft.

[series8217]

I added emphasis in my original post and tweaked the thread title for those of you that thought the question was "what manifolds can I bolt up to an LS1 in an E36 and clear the steering shaft without modification". I've done enough research to know that no known manifolds fit without modification. Obviously anything can be modified enough to fit. This isn't a cost-cutting measure, and performance is not an issue either. I need something that looks mostly OEM so it passes a visual inspection.

All the manifolds were tried with exception of the LS4, but I don't think that will fit either.

Check out Braap's post on ls1 tech.

http://ls1tech.com/forums/14204144-post81.html

Thanks for the link! Those pictures are super helpful.

[hefftone]

No matter how many times people ask the question, the answer doesn't change

Yeah, but.....this is bimmerforums!!!!!

Btw the way, if an engine is transverse....which manifold is driver side?

[BRAAP]

As a profesional engine builder/machinist since the late '80's also well versed in engine swaps, it is my professional opinion that placement of the GM gen-III/IV poppet valve reciprocating Otto cycle powerplant in an inverted position with attention given to lubrication and liquid temp control nuances associated with an inverted installation as well as energy output redirected low and down through trans tunnel very well could yield the possibility of utilizing OE exhaust manifolds.

Jokes aside, if cutting and welding the iron manifolds on a genuinely professional level can be done, for comparable effort, new manifolds could be cast that fit perfectly and have no appearance of modification in the eyes of big brother, i.e. pass as OE, and be cast ideal from a clearance and breathing standpoint, expanding the E36 LSx market...

[series8217]

As a profesional engine builder/machinist since the late '80's also well versed in engine swaps, it is my professional opinion that placement of the GM gen-III/IV poppet valve reciprocating Otto cycle powerplant in an inverted position with attention given to lubrication and liquid temp control nuances associated with an inverted installation as well as energy output redirected low and down through trans tunnel very well could yield the possibility of utilizing OE exhaust manifolds.

Unfortunately the head would then be in the way of the steering shaft.

Jokes aside, if cutting and welding the iron manifolds on a genuinely professional level can be done, for comparable effort, new manifolds could be cast that fit perfectly and have no appearance of modification in the eyes of big brother, i.e. pass as OE, and be cast ideal from a clearance and breathing standpoint, expanding the E36 LSx market...

I can definitely mod the stock manifolds more easily (and cheaply) than having new iron manifolds cast and machined. Keep in mind some of the OE LSx manifolds are hydroformed steel; that makes them much easier to modify. I will definitely be looking at those before I decide to work on the irons.

Besides that, it would also be cheaper to just pay the $3k - $9k to have Vorshlag headers run through CARB-testing and get them approved in California, than to have the tooling made for new cast iron exhaust manifolds. I do not intend to personally fund such an endeavor since I haven't dedicated myself to an E36 chassis for my project, but if enough people go together to do it, I would be willing to contribute.

Yeah, but.....this is bimmerforums!!!!!

Btw the way, if an engine is transverse....which manifold is driver side?

The answer is in my original post if you look hard enough .

the front manifold (driver side for RWD)

No matter how many times people ask the question, the answer doesn't change

I haven't seen this question posed with respect to fudging manifolds just to pass a California BAR referee inspection. If I'm wrong please direct me to the thread; I'd love to read it. I know the question has been posed many times with purpose of finding off-the-shelf manifolds as-is to save money over the REAL solutions, but since the motivation there is cost-saving, many approaches to modifying OEM manifolds may have been disregarded.

[BRAAP]

I recall first year "Y" body and "F" body were hydroformed exhaust manis, definitely modifiable. What others were of the steel tube design?

Looked at the LS4 manifolds, like the other OE manifolds looked at/mocked up by myself and others, they will not work due to dumping downward as they exit the head. In the E36 LSx, #7 primary must exit straight, (horizontal), or slightly up-hill to clear the steering shaft and also immediately route forward while still being horizontal to clear the brake booster, (the link in Kaane's post above to a post I wrote shows this particular area in plan-view and elevation-view). Essentially any exhaust manifold that exits #7 cylinder downward will not work unless it is modified as described above.

Curious, how does a modified exhaust manifold pass BAR if it is considered part of the emissions equipment and modification to emission equipment is not allowed?

[invictuse36]

He is hoping that the referee doesn't notice that the manifold is infact modified. The old 1-2 glance over and sign off.

[hefftone]

The answer is in my original post if you look hard enough

LOL, touche!!!!

[rao]

I haven't seen this question posed with respect to fudging manifolds just to pass a California BAR referee inspection. If I'm wrong please direct me to the thread; I'd love to read it. I know the question has been posed many times with purpose of finding off-the-shelf manifolds as-is to save money over the REAL solutions, but since the motivation there is cost-saving, many approaches to modifying OEM manifolds may have been disregarded.

The reason behind the question STILL doesn't change the answer to the question.

If you are going to modify the manifolds and you think you can do it in a way that will pass a BAR inspection, then pick whichever manifolds that you like and get to work. That also doesn't change the fact that stock manifolds are not going to fit.

I also like the suggestion that stock manifolds are not a "REAL" solution; I believe that there are millions of LSX powered vehicles on the road that suggest otherwise.

[monger]

I've posted these pics before, but I'll save you the search. If you can find a set of block hugger headers that are carb certified, you can make it work this way:

[Kaane]

JBA is only company I know that makes carb certified block huggers. Putting Vorshlag headers through carb certification will never happen since they relocate the catalytic converter location and would never pass.

[bimerok]

^ speaking of which, not only the hugger/stock headers would need to fit the application, but they also need to have the cats in the original location. Don't they? And that might be even harder task.

[series8217]

I recall first year "Y" body and "F" body were hydroformed exhaust manis, definitely modifiable. What others were of the steel tube design?

Those are the ones I'm aware of. The Z06 has a nice hydroformed header. I technically can't pass with that one since I'd have to be using an LS7, but it might be OK. The F-body ones look better on paper as far as smog goes (not fitment).

Curious, how does a modified exhaust manifold pass BAR if it is considered part of the emissions equipment and modification to emission equipment is not allowed?

Technically it doesn't. If it looks close enough to stock they may not notice or care. Completely fabricated headers are obvious and easy fail inspection.

He is hoping that the referee doesn't notice that the manifold is infact modified. The old 1-2 glance over and sign off.

Basically yes, though the inspection is quite thorough. However, it's unlikely that the referee will question a part which is obviously OEM. They might even let slight modifications slip by even if they notice them, but that's up to the referee.

That said, it's a very popular swap motor so I could be wrong with how much they will look into it. The worst case (besides noticing modifications deciding they're not allowed) is I have to specify my donor vehicle as the one which the manifolds I use came from.

JBA is only company I know that makes carb certified block huggers. Putting Vorshlag headers through carb certification will never happen since they relocate the catalytic converter location and would never pass.

It actually doesn't matter if they relocate the cat as long as it still gets hot enough to pass the test. That's the whole point of CARB testing -- to verify that whatever changes were made do not significantly reduce the emissions of the vehicle.

My friend runs a shop that has gone through basically this exact same process with another vehicle. See: http://www.westcoastfiero.com/engine...nversions.html
This is an intake/header/cat/muffler system which they got through the whole CARB EO process. Obviously the cat can't be placed in the original position it was at in the donor car.. it would be out behind the rear bumper on the Fiero chassis.

^ speaking of which, not only the hugger/stock headers would need to fit the application, but they also need to have the cats in the original location. Don't they? And that might be even harder task.

Yes, good observation. In fact that's true for all swaps unless the pre-cat exhaust has a CARB EO number.

However, it turns out that this rule is almost universally ignored by the referees. They know you're going to have to relocate the cat, so most of them follow a rule of thumb: if it's the same distance (or closer) to the exhaust manifold / header outlet flange as it was on the donor vehicle, it's ok.

I had to deal with this on my Fiero. I did a swap which there are no CARB-approved aftermarket parts for. The stock cat location would have been behind the rear bumper of the car, so I just used an extremely tight 90* turn off the exhaust manifold and put the cat sideways. It's actually closer to the manifold than it would have been in the donor car, and it passed the BAR inspection. I know many others that have been through the same process.

[Pzary3233]

I HAVE mocked the W body header... it is even more in the way then other designs.... It looks cool though!

In a turbo application it would be awesome forward facing.

Your best bet would be a set of really cut up truck manifolds... In all actuality you'll need to get a car, LSx motor, and a choose your mounting system (Vorshlag, NAHR, JTR, NASH, etc) or fabricate your own that allows optimum engine placement for YOUR intended purpose. Steering can be modified to a great extent if the will is there. The problem being that you'll probably cut up the car more to get the steering worked out then you will to make manifolds fit.

[Bimmer Man]

What if you used heat shielding to cover the manifold?

I am seriously considering running an LSx engine in my e36 but as research and this thread has shown, OEM headers just won't work. If I push forward, I was going to get the headers ceramic coated, run heat shielding so the headers are not visible and then place the cats under the car where they are in the e36.

Does a referee have to visually see the headers? Would he make you take them off for inspection?

[Kaane]

it's very easy to tell if the car has factory style manifolds vs a header, you won't fool a bar station.

[Pzary3233]

^ VERY VERY true.

[Bimmer Man]

What did you do to pass? I see you are from Irvine.

[Kaane]

Who said I passed lol, I knew it was next to impossible, so I did not bother. I smogged it just before I took it apart, so I have 2 years lol. In 2 years who knows! maybe some magic manifold will exist.

[invictuse36]

Well as much as California sucks..... i know of many people running FI setups that surely arnt Carb legal. You just have to find the smog shop they use, and hope a cop never busts you for street racing.


Speaking of, does anyone know of some ls1 engine covers that read BMW instead of Corvette?

[Pzary3233]

Plastic welding is your friend :-)